Reception apparatus, reception method, transmission apparatus, transmission method, program, and broadcast system

ABSTRACT

To realize a service of data content that can interlock with AV content of programs without providing a band for broadcasting data content in a broadcast band for digital television broadcast, provided is a reception apparatus that receives an audio and/or video (AV) content, the apparatus including: an extraction section to extract trigger information from the AV content, the trigger information being related to an application program that is executed interlocking with a progress of the AV content, the trigger information including a trigger type; and a control section to control one of an activation of the application program, a dispatch of an event of the application program being executed, and an end of the application program being executed in accordance with the trigger type included in the extracted trigger information.

TECHNICAL FIELD

The present invention relates to a reception apparatus, a receptionmethod, a transmission apparatus, a transmission method, a program, anda broadcast system, and more particularly, to a reception apparatus, areception method, a transmission apparatus, a transmission method, aprogram, and a broadcast system that are suitable for use in a case ofexecuting data content while interlocking with the progress of AVcontent corresponding to so-called television programs in digitaltelevision broadcast, for example.

BACKGROUND ART

From the past, the digitization of television broadcast has beenpromoted in Japan and terrestrial digital broadcast, BS digitalbroadcast, and the like are widely diffused. In addition, the digitaltelevision broadcast such as terrestrial digital broadcast realizes notonly broadcast of AV content corresponding to so-called televisionprograms but also so-called data content. Using data content, display ofinformation related to a television program being broadcast (AVcontent), display of information that is not related to a televisionprogram being broadcast (announcement of another television program,news, weather report, traffic information, etc.), and execution ofapplications that interlock with a television program being broadcast(AV content) are enabled (see, for example, Patent Literature 1).

It should be noted that the broadcast of data content in Japan isrealized by securing a band for data broadcast in a broadcast band fordigital television broadcast in advance at a time of digitizingtelevision broadcast, and broadcasting data content using this band.

Incidentally, in the digital television broadcast in the United States,one corresponding to the data broadcast in the digital televisionbroadcast in Japan has not been realized. In other words, the broadcastband in the current digital television broadcast in the United States isoccupied by a video band, an audio band, and a control information bandas shown in FIG. 1A, and a band for broadcasting data content is notprovided. Therefore, to secure a band for broadcasting data content inthe limited broadcast band of the digital television broadcast, thevideo band and the audio band are necessary to be reduced in size asshown in FIG. 1B.

CITATION LIST Patent Literature

[PTL 1]

Japanese Patent Application Laid-open No. 2006-50237

SUMMARY OF INVENTION

However, to reduce the sizes of the video band and the audio band tosecure the band for broadcasting data content leads to the deteriorationof image quality and sound quality of television programs, and resultsin undesirable performance.

In addition, since a retransmission system of digital televisionprograms using a CATV (cable-TV) network is widely used in the UnitedStates, the following problems may also be caused.

FIG. 2 shows an example of a structure of a retransmission system ofdigital television programs using a CATV network. The retransmissionsystem mainly includes a broadcast or output apparatus 1, a CATVretransmission apparatus 2, a CATV network 3, a digital television set4, a set top box (STB) 5, and a television set 6.

The broadcast apparatus 1 installed in a broadcast station or the likebroadcasts, or alternatively, outputs to a transmitter, a digitaltelevision broadcast signal. For example, the broadcast may be byterrestrial waves or satellite waves. The CATV retransmission apparatus2 installed in a cable TV station or the like receives digitaltelevision broadcast that has been broadcast, and removes unnecessaryinformation therefrom and adds information specific to CATV thereto, tothereby retransmit the resultant to the digital television set 4, theset top box 5, and the like via the CATV network 3.

The CATV retransmission apparatus 2 includes a tuner 11, a PID filter 12for filtering a packet of a predetermined packet ID, a CATV-specificsignal generation section 13, a multiplexing section 14, and amodulation section 15.

The tuner 11 receives and demodulates a digital television broadcastsignal of each channel and outputs a resultant TS (transport stream) tothe PID filter 12. The PID filter 12 removes a packet (that is notrelated to AV content as television program) corresponding to apredetermined packet ID from the TS and outputs the TS to themultiplexing section 14. The CATV-specific signal generation section 13generates a packet storing information specific to a relevant CATVstation and outputs the packet to the multiplexing section 14. Themultiplexing section 14 multiplexes the output of the PID filter 12 andthe output of the CATV-specific signal generation section 13 and outputsthe resultant to the modulation section 15. The modulation section 15modulates the output of the multiplexing section 14 by a modulationsystem suitable for the CATV network 3 and retransmits the resultant tothe digital television set 4, the set top box 5, and the like via theCATV network 3.

The digital television set 4 that supports CATV receives the TS of theretransmitted digital television broadcast via the CATV network 3 anddecodes the TS, and then displays a resultant video and outputs audio atthe same time.

The set top box 5 that supports CATV receives the TS of theretransmitted digital television broadcast via the CATV network 3 anddecodes the TS, and then outputs resultant video and audio signals tothe television set 6 via an HDMI cable or the like. The television set 6displays the video and outputs the audio based on the video signal andthe audio signal input from the set top box 5 via the HDMI cable or thelike.

As described above, in the CATV retransmission apparatus 2, a packet(that is not related to AV content as television program) correspondingto a predetermined packet ID is removed from the TS of the digitaltelevision broadcast signal by the PID filter 12. As a result, even if aband for broadcasting data content is secured in the broadcast band asshown in FIG. 1B, there may be caused a case where packets storing thedata content are removed by the PID filter 12.

In view of the circumstances as described above, it is desirable torealize a service of data content that can interlock with the progressof a television program without providing a band for data broadcast in abroadcast band for digital television broadcast.

According to an embodiment of the present invention, the applicationprogram can be controlled interlocking with the progress of the AVcontent such as a television program without providing a band for databroadcast in a broadcast band for digital television broadcast.

According to another embodiment of the present invention, there isprovided a reception apparatus that receives an audio and/or video (AV)content, the apparatus including: an extraction section to extracttrigger information (or other information regarding the data content)from the AV content, the trigger information being related to anapplication program that is executed interlocking with a progress of theAV content, the trigger information including a trigger type; and acontrol section to control one of an activation of the applicationprogram, a dispatch of an event of the application program beingexecuted, and an end of the application program being executed inaccordance with the trigger type included in the extracted triggerinformation.

According to another embodiment of the present invention, there isprovided a transmission apparatus that transmits an audio and/or video(AV) content, the apparatus including a transmission section to storetrigger information in the AV content to be transmitted, the triggerinformation being related to an application program that is executed bya reception apparatus, interlocking with a progress of the AV content.The trigger information includes a trigger type that includes at leastone of an application activation of instructing an activation of theapplication program, an application event of instructing a dispatch ofan event of the application program being executed, and an applicationend of instructing an end of the application program being executed.

According to yet another embodiment of the present invention, there isprovided an apparatus for providing access to data content on a server.The apparatus may include an insertion unit configured to insertinformation regarding the data content into a digital televisionbroadcast signal, the digital television broadcast signal not includingthe data content; and an output unit configured to output the digitaltelevision broadcast signal for broadcast.

According to yet another embodiment of the present invention, there isprovided an apparatus for receiving data content. The apparatus mayinclude a receiving unit configured to receive, over a firstcommunication channel, a digital television broadcast signal containinginformation regarding the data content accessible over a secondcommunications channel; and an extracting unit configured to extract theinformation regarding the data content from the digital televisionbroadcast signal.

According to yet another embodiment of the present invention, there isprovided a method for providing access to data content on a server. Themethod may include inserting information regarding the data content intoa digital television broadcast signal, the digital television broadcastsignal not including the data content; and outputting the digitaltelevision broadcast signal.

According to yet another embodiment of the present invention, there isprovided a method for receiving data content. The method may includereceiving, over a first communication channel, a digital televisionbroadcast signal containing information regarding the data contentaccessible over a second communications channel; and extracting theinformation regarding the data content from the digital televisionbroadcast signal.

According to yet another embodiment of the present invention, there isprovided a system for delivering data content. The system may include abroadcasting apparatus configured to broadcast a digital televisionbroadcast signal over a first communication channel, the digitaltelevision broadcast signal including information regarding the datacontent and not including the data content; and a server configured totransmit the data content over a second communications channel inresponse to a request for the data content.

According to yet another embodiment of the present invention, there isprovided a computer-readable storage medium storing instructions which,when executed by a processor, cause a computer to perform a method. Themethod may include inserting information regarding data content into adigital television broadcast signal, the digital television broadcastsignal not including the data content; and outputting the digitaltelevision broadcast signal.

According to yet another embodiment of the present invention, there isprovided a computer-readable storage medium storing instructions which,when executed by a processor, cause a computer to perform a method. Themethod may include receiving, over a first communication channel, adigital television broadcast signal containing information regarding thedata content; extracting the information regarding the data content fromthe digital television broadcast signal; and acquiring the data contentover a second communications channel using the information regarding thedata content.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A and 1B are diagrams each showing a broadcast band for digitaltelevision broadcast.

FIG. 2 is a diagram showing an example of a structure of an existingCATV retransmission system.

FIG. 3 is a diagram showing a structural example of a broadcast systemto which an embodiment of the present invention is applied.

FIG. 4 is a block diagram showing a structural example of a receptionapparatus to which the embodiment of the present invention is applied.

FIG. 5 is a diagram showing a concept of transmitting a PCR packet of aTS including trigger information.

FIG. 6 is a diagram showing a specific arrangement of the triggerinformation in the PCR packet.

FIG. 7 is a diagram showing items included in the trigger information.

FIG. 8 is a diagram showing an example of a syntax of the triggerinformation.

FIG. 9 is a flowchart for describing trigger information processing.

FIGS. 10A and 10B are each diagrams for describing distribution ofaccess to a server.

FIG. 11 is a display example of a screen at a time when a data broadcastapplication is executed.

FIG. 12 is another display example of the screen at the time when thedata broadcast application is executed.

FIGS. 13A and 13B are diagrams each showing an example in which thetrigger information is embedded in a base band video signal.

FIG. 14 is a block diagram showing a structural example of a computer.

DESCRIPTION OF EMBODIMENTS

Hereinafter, best modes for carrying out the present invention(hereinafter, referred to as embodiments) will be described in detailwith reference to the drawings.

(1. First Embodiment)

[Structural Example of Broadcast System]

FIG. 3 shows a broadcast system 30 as this embodiment. The broadcastsystem 30 realizes a service of data content that can interlock with AVcontent of television programs without providing a band for broadcastingthe data content in a broadcast band for digital television broadcast inthe current United States, for example.

The broadcast system 30 includes a broadcast apparatus 41 and a server42 that are installed on a broadcast station side, and a receptionapparatus 60 installed on a receiver side.

The broadcast apparatus 41 outputs or transmits a digital televisionbroadcast signal. It is assumed that a broadcast band of the digitaltelevision broadcast signal is occupied by a video band, an audio band,and a control information band as shown in FIG. 1A and a band forbroadcasting data content is not provided.

Further, the broadcast apparatus 41 stores or inserts, at apredetermined timing, information regarding the data content, such astrigger information, in a packet that is defined not to be removed byCATV apparatus, such as a Program Clock Reference (PCR) packet in a TSpacket constituting a TS (transport stream) of the digital televisionbroadcast signal. Then, the broadcast apparatus 41 transmits the digitaltelevision broadcast signal storing the trigger information.

Here, the information regarding the data content may entirely be triggerinformation including information indicating an execution timing of adata broadcast content, information indicating an acquisition source ofa data broadcast content, and the like. The trigger information will bedescribed in detail with reference to FIGS. 5 to 8.

The server 42 supplies a data broadcast content or the like to thereception apparatus 60 in response to a request from the receptionapparatus 60 that accesses the server 42 via an Internet 50. Thereception apparatus 60 receives the digital television broadcast signalthat is broadcast from the broadcast apparatus 41 over a firstcommunications channel, such as a terrestrial RF broadcast, and acquiresvideo and audio of an AV content corresponding to a television program,to thereby output the acquired video and audio to a monitor (not shown).Further, the reception apparatus 60 accesses the server 42 over a secondcommunications channel, such as via the Internet 50, and acquires a databroadcast content. It should be noted that the reception apparatus 60may exist individually or may be incorporated into a television set or avideo recorder, for example.

[Structural Example of Reception Apparatus]

FIG. 4 shows a structural example of the reception apparatus 60. Thereception apparatus 60 includes a receiving unit such as a tuner 61, anextracting unit such as a demultiplexing section 62, an audio decoder63, an audio output section 64, a video decoder 65, a trigger detectionsection 66, a video output section 67, a controller 68, a memory 69, anoperation section 70, a recording section 71, a communication I/F 72,and a browser 73.

The tuner 61 receives and demodulates a digital television broadcastsignal corresponding to a channel selected by a user and outputs aresultant TS to the demultiplexing section 62. The demultiplexingsection 62 demultiplexes the TS input from the tuner 61 into an encodedaudio signal, an encoded video signal, and a control signal, and outputsthe encoded audio signal, the encoded video signal, and the controlsignal to the audio decoder 63, the video decoder 65, and the controller68, respectively.

Further, the demultiplexing section 62 extracts a PCR packet includingthe trigger information arranged in the TS and outputs the PCR packet tothe controller 68.

The audio decoder 63 decodes the input encoded audio signal and outputsa resultant audio signal to the audio output section 64. The audiooutput section 64 outputs the input audio signal to a subsequent stage(for example, speaker).

The video decoder 65 decodes the encoded video signal thus input andoutputs a resultant video signal to the trigger detection section 66 andthe video output section 67. The trigger detection section 66 constantlymonitors the input video signal and detects trigger information embeddedin the video signal (which corresponds to another transmission method(described later) different from the transmission method in the casewhere the trigger information is stored in the PCR packet). The videooutput section 67 outputs the video signal input from the video decoder65 to a subsequent stage (for example, monitor). Further, the videooutput section 67 combines a video of a data broadcast content that isinput from the browser 73 and the video signal input from the videodecoder 65 and outputs the combined resultant to the subsequent stage.It should be noted that the output from the audio output section 64 andthe video output section 67 to the subsequent stages can be performedusing an HDMI (High-Definition Multimedia Interface) cable.

The controller 68 controls the entire reception apparatus 60 byexecuting a control program recorded in the memory 69. Further, thecontroller 68 controls acquisition, activation, event dispatch, end, andthe like of an application program for implementing a data broadcastcontent that interlocks with a television program based on the triggerinformation input from the demultiplexing section 62 (or triggerdetection section 66).

In the memory 69, a control program executed by the controller 68 isrecorded. The control program can be updated based on a digitaltelevision broadcast signal or update data acquired via the Internet 50.The operation section 70 receives various operations from the user andnotifies the controller 68 of operation signals corresponding to thevarious operations.

The recording section 71 stores a downloaded data broadcast applicationin a built-in recording medium in a case where the data broadcastapplication is distributed using a digital television broadcast signal.

The communication I/F 72 is connected to the server 42 via the Internet50 under the control of the browser 73. The browser 73 acquires anapplication program for data broadcast (hereinafter, referred to simplyas data broadcast application) from the server 42 via the communicationI/F 72 and the Internet 50 under the control of the controller 68.

[Details of Trigger Information]

FIG. 5 shows a concept of a case where the trigger information stored inPCR packets of a TS is transmitted. As shown in FIG. 5, the triggerinformation is not stored in all PCR packets but stored in PCR packetsat only adequate timings for interlocking with an AV contentcorresponding to a television program. Since the PCR packet is a type ofpacket defined to remain in a transport stream after processing by aCATV retransmission system, the PCR packet passes through a PID filter12 of a CATV retransmission apparatus 2 shown in FIG. 2 in general. Thetrigger information can thus be notified to a reception apparatus usinga CATV network (digital television set 4 of FIG. 2).

It should be noted that depending on the contents of the triggerinformation, the same trigger information is transmitted a plurality ofnumber of times in consideration of a case where the trigger informationis not received by the reception apparatus 60.

FIG. 6 shows a position at which the trigger information is stored in aPCR packet. The PCR packet is obtained by storing a PCR in“adaptation_field” of a TS packet, and the trigger information(TriggerInfo_descriptor) is stored in “transport_private_data_byte”subsequent to the PCR. It should be noted that in a case where thetrigger information is stored, “transport_private_data_flag” of “Variousflags” provided before the PCR is set to 1.

FIG. 7 shows an example of information items included in the triggerinformation.

A trigger ID is information for identifying relevant triggerinformation. In the case where the same trigger information istransmitted a plurality of number of times, the trigger IDs of therespective pieces of trigger information are the same. Further, the sametrigger ID is imparted to pieces of trigger information in which onlyserver access distribution parameters described later are different. Atrigger type indicates that the trigger information is in any state of“application execute” (that instructs acquisition and activation of databroadcast application), “application terminate” (that instructs end ofdata broadcast application being executed), “inject-event” thatinstructs dispatch of event (update of displayed contents etc.) in databroadcast application being executed), and “precache” (that instructsonly acquisition of data broadcast application).

An application ID is information for identifying a data broadcastapplication corresponding to the trigger information. An applicationtype is information indicating a type of the data broadcast application(for example, html and java) corresponding to the trigger information. Abusiness company ID is information for identifying a business company(broadcast station etc.) that performs a service of executing the databroadcast application corresponding to the trigger information. Anapplication URL (Uniform Resource Locator) is a URL of an acquisitionsource, that is, information regarding a location, of the data broadcastapplication (in this case, server 42) in the case where the trigger typeis “application execute” or “precache”. An accumulation application IDis described only when an accumulated data broadcast application to beactivated (already acquired data broadcast application) is designatedwithout instantly acquiring a data broadcast application in the casewhere the trigger type is “application execute”.

An automatic activation flag is described in the case where the triggertype is “application execute” and is set to on or off. When theautomatic activation flag is on, “automatic execute” (to automaticallyactivate data broadcast application) is set. When the automaticactivation flag is off, “manual activation” (to prompt user to makeoperation input and activate data broadcast application in accordancewith operation input) is set.

An application end time is information that indicates a time at whichthe data broadcast application being executed is ended in the case wherethe trigger information whose trigger type is “application terminate” isnot received.

A server access distribution parameter is a value N (integer of 2 ormore) for distributing access, or controlling attempts to access server42 among a plurality of receiver devices so as to avoid concentration ona certain period of time when each reception apparatus 60 that hasreceived the trigger information acquires a data broadcast applicationfrom the server 42. For example, to distribute access to the server 42from a possible large number of reception apparatuses 60 into 4 times,it is only necessary to transmit the same trigger information 4 times,and set the server access distribution parameter N of the first triggerinformation to 4, the server access distribution parameter N of thesecond trigger information to 3, the server access distributionparameter N of the third trigger information to 2, and the server accessdistribution parameter N of the fourth trigger information to 1. Thatis, the access distribution parameter may be sequentially inserted ortransmitted as a plurality of values. It should be noted that in a casewhere the trigger information is not related to the access to the server42, the server access distribution parameter N has only to be set to 1.Details of the server access distribution parameter will be describedlater with reference to FIGS. 10A and 10B.

An application name is a name of a data broadcast application to bepresented to the user in a case where the automatic activation flag isset to “manual activation”. An event ID is information for identifyingan event in a case where the trigger type is set to “inject-event”. Itshould be noted that the trigger information does not include all theitems described above generally, but includes only items necessary atthat timing.

FIG. 8 shows an example of a syntax of the trigger information. Itshould be noted that the syntax of the trigger information isarbitrarily set and is not limited to that of FIG. 8.

[Description on Operation]

Next, an operation at a time when the reception apparatus 60 receivesthe trigger information (hereinafter, referred to as trigger informationprocessing) will be described.

FIG. 9 is a flowchart for describing the trigger information processing.The trigger information processing is executed repeatedly when the useris viewing a television program, that is, during a period of time inwhich a digital television broadcast signal is being received.

In Step S1, the controller 68 waits until a PCR packet including triggerinformation is received based on an input from the demultiplexingsection 62. Then, when the PCR packet including trigger information isreceived, the processing proceeds to Step S2.

In Step S2, the controller 68 extracts the trigger information from thereceived PCR packet and judges whether processing of Step S4 andsubsequent steps are already performed on the trigger information. Whenit is judged that the processing of Step S4 and subsequent steps arealready performed, the processing returns to Step 1 and repeats thesubsequent steps. Conversely, when it is judged that processing of StepS4 and subsequent steps are not performed on the trigger information,the processing proceeds to Step S3.

In Step S3, the controller 68 judges whether the current processing isvalid (whether the processing proceeds to Step S4 and subsequent stepsto perform server access) or invalid (whether the processing returns toStep S1) based on the server access distribution parameter N of thetrigger information. It should be noted that in a case where the serveraccess distribution parameter N is not described in the triggerinformation, the processing proceeds to Step S4.

Here, the judgment in Step S3 as to whether the current processing isvalid or invalid will be described in detail with reference to FIGS. 10Aand 10B.

As shown in FIG. 10B, in order to distribute access to the server 42from a possible large number of reception apparatuses 60 into 4 times asan intention of the broadcast station side, the same trigger informationis transmitted 4 times from the broadcast apparatus 41, and the serveraccess distribution parameter N may have a plurality of values. Forexample, the server access distribution parameter N of the first triggerinformation is set to 4, the server access distribution parameter N ofthe second trigger information to 3, the server access distributionparameter N of the third trigger information to 2, and the server accessdistribution parameter N of the fourth trigger information to 1.

In response to this, the controller 68 of the reception apparatus 60judges validity or invalidity based on random numbers or the like underthe condition in which validity is judged in the probability of 1/N,that is, the server access distribution parameter N corresponds todifferent probabilities of access to the server.

As a result, assuming that 10,000 reception apparatuses 60simultaneously execute the trigger information processing, theprocessing is judged to be valid in about 2,500 (=10,000/4) receptionapparatuses 60 by the first trigger information (server accessdistribution parameter N=4), additionally in about 2,500 (=7,500/3)reception apparatuses 60 by the second trigger information (serveraccess distribution parameter N=3), additionally in about 2,500(=5,000/2) reception apparatuses 60 by the third trigger information(server access distribution parameter N=2), and in the remaining(=2,500/1) reception apparatuses 60 by the fourth trigger information(server access distribution parameter N=1). Accordingly, the probabilityof access by the plurality of reception apparatuses increases withsuccessive requests to the server.

With referring back to FIG. 9, in Step S4, the controller 68 judges towhich of “application execute”, “inject-event”, “application terminate”,and “precache” a trigger type of the trigger information is set.

When a trigger type of the trigger information is judged to be“application execute” in Step S4, the processing proceeds to Step S5. InStep S5, the controller 68 judges whether an accumulation application IDis designated in the trigger information and a data broadcastapplication corresponding thereto is already accumulated in therecording section 71. When it is judged that an accumulation applicationID is not designated and a data broadcast application correspondingthereto is not accumulated, the processing proceeds to Step S6. In StepS6, the controller 68 controls the browser 73 to access the server 42that corresponds to an application URL of the trigger information andacquire a data broadcast application that corresponds to an applicationID of the trigger information. Here, in a case where a relevant databroadcast application is already acquired from the server 42 thatcorresponds to the application URL in Step S15 described later andprecached, the data broadcast application is used. After that, theprocessing proceeds to step S8.

Conversely, when it is judged in Step S5 that an accumulationapplication ID is designated in the trigger information and a databroadcast application corresponding thereto is already accumulated inthe recording section 71, the processing proceeds to Step S7. In StepS7, the controller 68 controls the browser 73 to read the data broadcastapplication corresponding to the accumulation application ID of thetrigger information from the recording section 71. After that, theprocessing proceeds to Step S8.

In Step S8, the controller 68 judges whether an automatic activationflag of the trigger information is set to “automatic execute”.

When it is judged in Step S8 that an automatic activation flag of thetrigger information is not “automatic activation” (that is, the flag isset to “manual activation”), the processing proceeds to Step S9. In StepS9, the browser 73 prompts the user to make an activation operation ofthe data broadcast application by displaying, for example, “Execute(application name)?” on a screen based on the control by the controller68. When it is judged in Step S10 that an activation operation has beeninput by the user in response to the prompt display, the processingproceeds to Step S12. In Step S12, the browser 73 activates the databroadcast application that has been acquired in Step S6 or read in StepS7 under the control of the controller 68. After that, the processingreturns to Step S1 and repeats Step S1 and the subsequent steps.

It should be noted that when it is judged that an activation operationis not input by the user in Step S10 after the prompt display in Step S9and that a predetermined period of time has elapsed without anactivation operation input by the user in Step S11, the processingreturns to Step S1 and repeats Step S1 and the subsequent steps.

It should be noted that when it is judged in Step S8 that an automaticactivation flag of the trigger information is set to “automaticactivation”, the processing proceeds to Step S12. In Step S12, thebrowser 73 activates the data broadcast application that has beenacquired in Step S6 or read in Step S7 under the control of thecontroller 68. After that, the processing returns to Step S1 and repeatsStep S1 and the subsequent steps.

When it is judged in Step S4 that a trigger type of the triggerinformation is “inject-event”, the processing proceeds to Step S13. InStep S13, only when an application ID of the trigger information ismatched to an application ID of the data broadcast application beingoperated, the controller 68 controls the browser 73 to dispatch(execute) an event corresponding to an event ID of the triggerinformation in the application being operated. After that, theprocessing returns to Step S1 and repeats Step S1 and the subsequentsteps.

When it is judged in Step S4 that a trigger type of the triggerinformation is “application terminate”, the processing proceeds to StepS14. In Step S14, only when an application ID of the trigger informationis matched to an application ID of the data broadcast application beingoperated, the controller 68 controls the browser 73 to end theapplication being operated. After that, the processing returns to StepS1 and repeats Step S1 and the subsequent steps.

It should be noted that even when the trigger information whose triggertype is “application terminate” is not received, the data broadcastapplication being operated is ended when an application end time comes,the application end time being described in the trigger information whenthe data broadcast application being operated has been activated.

When it is judged in Step S4 that a trigger type of the triggerinformation is “precache”, the processing proceeds to Step S15. In StepS15, the controller 68 controls the browser 73 to access the server 42corresponding to an application URL of the trigger information andacquire a data broadcast application corresponding to an application IDof the trigger information, to thereby store the data broadcastapplication in a storage means such as a cache memory included in thebrowser 73. After that, the processing returns to Step S1 and repeatsStep S1 and the subsequent steps.

When the trigger type is “precache” as in Step S15, before a broadcasttime of a television program to be interlocked comes, a correspondingdata broadcast application can be acquired. As a result, thecorresponding data broadcast application can be executed simultaneouslywith the start of the television program to be interlocked. In addition,an effect of distributing the concentration of access to the server 42is expected. The description on the trigger information processing isended up to here.

[Display Example of Screen when Data Broadcast Application is Executed]

FIG. 11 shows a transition of a screen at a time when a data broadcastapplication is executed interlocking with the progress of a televisionprogram in a case where the automatic activation flag of the triggerinformation is off (“manual activation”).

When the trigger information whose trigger type is “application execute”and automatic activation flag is off (“manual activation”) is receivedduring a time when the user is viewing a television program, acorresponding data broadcast application is acquired. Next, anindication that prompts the user to make an activation operation of thedata broadcast application is displayed to be superimposed on a video ofthe television program. When the user inputs the activation operation inresponse to the prompt, the data broadcast application is activated andthe display of the screen is changed into a combination of a videocorresponding to the data broadcast application and the video of thetelevision program.

When the trigger information whose trigger type is “inject-event” isreceived in a state where the data broadcast application is beingexecuted, an event corresponding to an event ID of the triggerinformation is dispatched in the data broadcast application beingexecuted. As a result, an area of the screen display that corresponds tothe data broadcast application is changed into a video corresponding tothe event ID of the trigger information.

After that, when the trigger information whose trigger type is“application terminate” is received, the data broadcast applicationbeing executed is ended and the video of the television program isdisplayed on the entire screen.

[Another Display Example of Screen when Data Broadcast Application isExecuted]

Incidentally, the data broadcast application that is executedinterlocking with the progress of a television program is notnecessarily accompanied with display on the screen. With use of such adata broadcast application, that data broadcast application can beexecuted without being known by the user of the reception apparatus 60.Such a data broadcast application is applicable to a case where anaudience survey of a television program is executed, for example.Specifically, whether the television program is being viewed is recordedin accordance with the trigger information whose trigger type is“inject-event”, and the recording results are notified to apredetermined server at a predetermined timing, with the result that anaudience rating of the television program can be investigated at atransmission interval of the trigger information whose trigger type is“inject-event”.

FIG. 12 shows a transition of a screen at a time when a data broadcastapplication without display on the screen is executed interlocking withthe progress of a television program in a case where the automaticactivation flag of the trigger information is on (“automaticactivation”).

When the trigger information whose trigger type is “application execute”and automatic activation flag is on (“automatic activation”) is receivedduring a time when the user is viewing a television program, acorresponding data broadcast application is acquired and activated. Itshould be noted that the display on the screen is not changed with thevideo of the television program displayed.

When the trigger information whose trigger type is “inject-event” isreceived in a state where the data broadcast application is beingexecuted, an event corresponding to an event ID of the triggerinformation is dispatched in the data broadcast application beingexecuted. In this case as well, the video of the television program isleft displayed and the display on the screen is not changed.

After that, when the trigger information whose trigger type is“application terminate” is received, the data broadcast applicationbeing executed is ended.

[Another Transmission Method of Trigger Information]

Though the trigger information is stored in the PCR packet of the TS tobe transmitted in the above description, the trigger information may beembedded in a base band video signal to be transmitted.

FIGS. 13A and 13B show two examples in which the trigger information isembedded in a base band video signal.

FIG. 13A shows an example in which the trigger information is changedinto a two-dimensional barcode and superimposed at a predeterminedposition in an image of the base band video signal (in this case, lowerright corner). FIG. 13B shows an example in which the triggerinformation is changed into a video code and combined into number linespositioned on a lower side of an image of the base band video signal.The trigger information of FIGS. 13A and 13B are detected by the triggerdetection section 66 of the reception apparatus 60.

Since the trigger information is arranged on the screen of thetelevision program in both FIGS. 13A and 13B, the trigger informationcan also be notified to, for example, a reception apparatus using a CATVnetwork (for example, television set 6 of FIG. 2).

Further, though the trigger information on the screen (two-dimensionalbarcode and video code) can be viewed by the user of the receptionapparatus 60 in both cases of FIGS. 13A and 13B, if this is notdesirable, the two-dimensional barcode or video code may be displayedafter being masked by the same pixels as those around thetwo-dimensional barcode or video code.

As described above, according to the broadcast system 30 to which theembodiment of the present invention is applied, the trigger informationrelated to data broadcast is embedded in a PCR packet or a base bandvideo signal to be transmitted, whereas a data broadcast application issupplied from a server via the Internet. As a result, a service of datacontent that can interlock with television programs can be realizedwithout providing a band for data broadcast in a broadcast band fordigital television broadcast.

Further, the access to the server can be distributed so as to avoid theconcentration thereof on a certain period of time.

In addition, it is also possible to realize a service of data contentthat can interlock with television programs in a case where digitaltelevision programs are retransmitted via a CATV network, a satellitecommunication network, or the like.

Incidentally, a series of processing described above can be executed byhardware and can also be executed by software. In a case where a seriesof processing is executed by software, a program constituting thesoftware is installed from a program recording medium to a computerincorporated in dedicated hardware, a general-purpose personal computercapable of executing various functions by installing various programs,or the like.

FIG. 14 is a block diagram showing a structural example of hardware of acomputer that executes the series of processing described above by aprogram.

In this computer 100, a CPU (Central Processing Unit) 101, a ROM (ReadOnly Memory) 102, and a RAM (Random Access Memory) 103 are connected toone another via a bus 104.

An input/output interface 105 is also connected to the bus 104.Connected to the input/output interface 105 are an input section 106, anoutput section 107, a storage section (that is, a computer-readablestorage medium) 108, a communication section 109, and a drive 110. Theinput section 106 includes a keyboard, a mouse, a microphone, and thelike. The output section 107 includes a display, a speaker, and thelike. The storage section 108 includes a hard disk, a nonvolatilememory, and the like, and may store instructions for execution by theCPU. The communication section 109 includes a network interface and thelike. The drive 110 drives removable medium 111 such as a magnet disc,an optical disc, a magneto-optical disc, or a semiconductor memory.

In the computer structured as described above, the CPU 101 loads aprogram having instructions stored in, for example, the storage section108 in the RAM 103 via the input/output interface 105 and the bus 104and executes the program, with the result that the series of processingdescribed above is performed.

It should be noted that the program executed by the computer may be aprogram with which processing is performed in a chronological orderalong the order described herein, or may be a program with whichprocessing is performed in parallel or at a necessary timing when acalling is made or the like.

Further, the program may be one processed by one computer or oneprocessed in a distributed manner by a plurality of computers. Inaddition, the program may be one transferred to a remote computer andthen executed.

Further, the system herein refers to a plurality of apparatuses, as awhole.

It should be noted that the embodiment of the present invention is notlimited to the embodiment described above and various changes can bemade without departing from the gist of the present invention.

The present application contains subject matter related to thatdisclosed in Japanese Priority Patent Application JP 2009-287228 filedin the Japan Patent Office on Dec. 18, 2009, the entire content of whichis hereby incorporated by reference.

REFERENCE SIGNS LIST

30 broadcast system

41 broadcast apparatus

42 server

60 reception apparatus

61 tuner

62 demultiplexing section

63 audio decoder

64 audio output section

65 video decoder

66 trigger detection section

67 video output section

68 controller

69 memory

70 operation section

71 recording section

72 communication I/F

73 browser

The invention claimed is:
 1. An apparatus comprising: circuitryconfigured to receive a transport stream of a digital televisionbroadcast signal having trigger information inserted into not allProgram Clock Reference (PCR) packets of the transport stream but onlyPCR packets at adequate timings to enable successful interlocking withan audio visual content on a network server; circuitry configured toextract the trigger information from the adequate timings of the PCRpackets to access data content interlocking with the audio visualcontent on the network server, wherein the trigger information comprisesa diffusion parameter which controls access timing to the network serverso as to avoid a concentration of access to the network server, andwherein the diffusion parameter indicates a period of time by whichaccess to the network server is to be delayed; and circuitry configuredto initiate access to the data content on the network server based onthe trigger information.
 2. The apparatus of claim 1, wherein the datacontent comprises an application program interlocking with the audiovisual content on the network server.
 3. The apparatus of claim 2,wherein the trigger information further comprises a trigger type tocontrol the application program including at least one of an activationof the application program and an end of the application program beingexecuted.
 4. The apparatus of claim 1, wherein the diffusion parameteris a discrete parameter which controls the access timing to the networkserver so as to avoid the concentration of access to the network server.5. The apparatus of claim 1, wherein the circuitry is further configuredto output an execution result of an application program that implementsthe data content.
 6. A method comprising: receiving a transport streamof a digital television broadcast signal having trigger informationinserted into not all Program Clock Reference (PCR) packets of thetransport stream but only PCR packets at adequate timings to enablesuccessful interlocking with an audio visual content on a networkserver; extracting the trigger information from the adequate timings ofthe PCR packets to access data content interlocking with the audiovisual content on the network server, wherein the trigger informationcomprises a diffusion parameter which controls access timing to thenetwork server so as to avoid a concentration of access to the networkserver, and wherein the diffusion parameter indicates a period of timeby which access to the network server is to be delayed; and accessingthe data content on the network server based on the trigger information.7. The method of claim 6, wherein the data content comprises anapplication program interlocking with the audio visual content on thenetwork server.
 8. The method of claim 7, wherein the triggerinformation further comprises a trigger type to control the applicationprogram including at least one of an activation of the applicationprogram and an end of the application program being executed.
 9. Themethod of claim 6, wherein the diffusion parameter is a discreteparameter which controls the access timing to the network server so asto avoid the concentration of access to the network server.
 10. Themethod of claim 6, further comprising outputting an execution result ofan application program that implements the data content.
 11. Anon-transitory computer-readable medium having embodied thereon aprogram, which when executed by a computer causes the computer toperform a method, the method comprising: receiving a transport stream ofa digital television broadcast signal having trigger informationinserted into not all Program Clock Reference (PCR) packets of thetransport stream but only PCR packets at adequate timings to enablesuccessful interlocking with an audio visual content on a networkserver; extracting the trigger information from the adequate timings ofthe PCR packets to access data content interlocking with the audiovisual content on the network server, wherein the trigger informationcomprises a diffusion parameter which controls access timing to thenetwork server so as to avoid a concentration of access to the networkserver, and wherein the diffusion parameter indicates a period of timeby which access to the network server is to be delayed; and accessingthe data content on the network server based on the trigger information.12. The non-transitory computer-readable medium of claim 11, wherein thedata content comprises an application program interlocking with theaudio visual content on the network server.
 13. The non-transitorycomputer-readable medium of claim 12, wherein the trigger informationfurther comprises a trigger type to control the application programincluding at least one of an activation of the application program andan end of the application program being executed.
 14. The non-transitorycomputer-readable medium of claim 11, wherein the diffusion parameter isa discrete parameter which controls the access timing to the networkserver so as to avoid the concentration of access to the network server.15. The non-transitory computer-readable medium of claim 11, wherein themethod further comprises: outputting an execution result of anapplication program that implements the data content.
 16. The apparatusof claim 1, wherein the diffusion parameter indicates a random period oftime by which access to the network server is to be delayed and an eventactivated.